Renewed violence in Iraq and the attack on the Baghdad Catholic cathedral at the beginning of November have drawn new attention to a largely forgotten problem: refugees. Forced to seek shelter in neighbouring states, millions want to know where their future lies.

Four million refugees have fled Iraq since the invasion of March 2003. Most are in the Middle East, a region which is now home to more than a third of the world's refugees.

These numbers are now bound to grow as Iraq's Nestorian or Assyrian Christians - nearly half a million - are increasingly targeted by insurgents. Jordan already provides shelter for over one million Palestinians and Syria nearly half that number. Crucially, despite the tolerance of their hosts, Iraqis' recent refuge in the neighbouring countries of Syria, Jordan, and Lebanon is rapidly becoming a protracted crisis. Unwilling to return and largely unable to emigrate further west or north, Iraq's refugees are in a perilous situation which needs to be recognised and addressed by the western powers whose military action created this humanitarian crisis. Off Guard

In the aftermath of the invasion of Iraq in March 2003, the western powers prepared for one million Iraqi 'refugees' to flee their country. Camps were set up to receive those who might try to escape the conflict. However, six months after the fall of the Baghdad regime, few Iraqis had actually fled. The international aid authorities had miscalculated the response to the invasion; the empty emergency camps were dismantled and pre-positioned food and equipment removed.

Three years later in 2006 the west was caught off-guard as hundreds of thousands of Iraqis fled to escape the deadly sectarian violence which had escalated with the Al-Askari Mosque bombing in Samarra that February. That single event became the iconic image of sectarian violence and the separation of communities which followed.

Nearly four million Iraqis fled in 2006 and 2007 with one to one and a half million crossing national borders into Syria and Jordan. The United Nations High Commissioner for Refugees (UNHCR) and affiliated non-governmental organisations raced to set up reception centres and provide emergency aid.

In both Syria and Jordan, Iraqis were not regarded as refugees by the host governments partially because neither country was a signatory to the 1951 United Nations Convention on the status of refugees.

Many of the Iraqis seeking asylum were from the educated, professional, and middle classes. A number managed to escape with savings, which helped ease their transition. Migrations during previous decades meant that there were some Iraqi social networks in the host countries.

Residual cultural memory of the Ottoman Empire's 'millet' system, which gave minority or religious communities a limited amount of power to regulate their own affairs, meant that Iraqi arrivals were generally tolerated if not actively comforted. Iraqis were also seen as temporary guests and Arab brothers because of earlier Pan-Arab regional aspirations. Prepare For Return

The US has taken the position that the American military 'surge' of 2007 has returned stability to Iraq and improved security dramatically such that US troops may be pulled out and redeployed elsewhere, for example to Afghanistan. International aid organisations have supported this view.

In April of last year UNHCR declared that security in Iraq had improved to the extent that people displaced from most regions of the country should no longer be viewed as refugees. It also began to prepare formally for the imminent return of large numbers.

Many Iraqi refugees keep their distance from the official agencies whose job it is to assist them. Despite a concerted effort over the past four years, UNHCR in Syria has registered only just over two hundred thousand Iraqis. The reasons can only be guessed at.

Some Iraqis claim to fear involuntary repatriation to Iraq if they formally register with the UN agency. Others worry about returning home to a country where the mixed ethnoreligious communities and the legacy of Ottoman tolerance have been wiped away. The recent targeting of Christians clearly points to the continuing seperation of peoples.

The Iraqi displacement crisis has reached a critical stage. International interest in the country is declining. Yet the lack of security, continuing civil conflict and economic uncertainty make amass refugee return unlikely.

More likely, refugees will remain in neighbouring states under increasingly difficult circumstances. As their savings diminish and their circularmovements into and out of Iraq to make money becomes more precarious, it is probable that irregular and long-distance migrations will occur in larger numbers.

The basic needs of refugees in exile in Syria and Jordan have been met by the host states with very limited financial assistance from the international community. Humanitarian aid from the European Commission, for example, between 2003 and 2008 provided $190.7 million for all displaced Iraqis - around nine dollars per person per year.

How long the host states will continue to provide asylum to their Iraqi 'guests' is a question which needs careful consideration. What will happen once Iraqis come to be perceived by their fellow Arab hosts as outstaying their welcome as 'temporary' guests or visitors?

Many Iraqis in Arab countries feel they are marooned with declining interest from governments and support networks. Third-country resettlement may yet emerge as a durable solution for them. In 2008, some 17,800 Iraqis were settled in third countries on programmes supported by UNHCR. Last year the pace of resettlement accelerated, with significant numbers admitted to the US. This time last year, UNHCR estimated that third country resettlement was required for a further five hundred thousand Iraqi refugees. However, in the current climate of opinion, resettlement options are likely to diminish unless the international humanitarian aid organisations reconsider.

The future well-being of Iraqi refugees clearly rests with the western powers which deposed Saddam Hussein's regime. Greater generosity and willingness to accept Iraqis for resettlement in the west might yet put European and American standards of morality on a par with the residual traditions of late Ottoman tolerance so clearly evident in the contemporary Arab east.

Dawn Chatty, University of Oxford, is the author of 'Displacement and Dispossession in the Modern Middle East, Cambridge University Press, 2010.